I believe in leaving people the heck alone. If someone I don't consider a close friend mentions religion I smile and nod and change the subject or walk away. If someone presses the matter I start pretending that person no longer exists. I know some crazy people of all religions, and I let them be crazy. None of my business.
No one in real life has ever directly asked me what my religion is, likely because I give off an aura that if you ask me I will hurt you. No one has ever invited me to their church, possibly because they wouldn't want me there anyways. If I was invited I'd smile and nod and decline. People may be like that here, but I have yet to encounter any. Most people here hand out fliers on the streets if anything, going for quantity over quality would be my guess.
It's different if I'm at some place where talking about religion is the whole point of course, like various internet forums. Or if a close friend brings up the subject. I really do enjoy talking about it and tend to have strong opinions about it. I don't care about "converting" people, but I like learning and helping people learn, for the sake of learning. I don't think anyone should ever randomly start a conversation about private matters with people they aren't close to though.